Incomplete dominance is described by a phenotype that is not completely dominant over another. Therefore, it will be a "blending" of colors in the case of this question, therefore the petals are pink. Codominance is when both dominant traits are expressed, therefore if white was considered dominant and red was also a dominant trait, the petals would have spots of white and red, with no pink. Polygenic inheritance is described by one characteristic influenced by multiple genes, which is not the case in this problem. Finally, epistasis involves the suppression of genes, however in this problem color is not suppressed.

Hardy-Weinberg equilibrium has a set of conditions that must be met in order for the population to have unchanging gene pool frequencies. There must be random mating, no mutation, no migration, no natural selection, and a large sample size.

It is not necessary for the population to be at carrying capacity. The population can grow or shrink while maintaining the gene pool.

If a population is in Hardy-Weinberg equilibrium, there is no evolution taking place in the population. One of the violations of Hardy-Weinberg equilibrium is selective mating. If birds prefer to mate with others that are similarly colored, then Hardy-Weinberg equilibrium is violated and the gene pool in the population is changing.

Hardy-Weinberg requires no migration, random mating, large population size, no natural selection, and no mutation.

The Hardy-Weinberg principle is a mathematical model proposing that, under certain conditions, the allele frequencies and genotype frequencies in a sexually reporoducing population will remain constant over generations. For this principle to hold true, evolution must essentially be stopped. The conditions to maintain the Hardy-Weinberg equilibrium are: no mutation, no gene flow, large population size, random mating, and no natural selection.

The Hardy-Weinberg equilibrium can be disrupted by deviations from any of its five main underlying conditions. Therefore mutation, gene flow, small population, nonrandom mating, and natural selection will disrupt the equilibrium.

Differentiation is the process whereby relatively unspecialized cells become specialized into particular tissue types. This is a standard process in organismal development, and is generally unrelated to evolutionary principles.

All of the answer choices are assumptions made when considering Hardy-Weinberg equilibrium. Thus, the model is not very realistic in nature, since these conditions are rarely met. Also, no natural selection is assumed to occur.

All the factors listed are factors that can change the genetic equilibrium of a population. Genetic drift is a random change in the frequency of alleles, as in this question—at first, there were more red-spotted fish than spotless fish (a 2:1 ratio), but once the random fishing took place, there were fewer red-spotted fish than spotless fish (a 1:3 ratio). This selection by chance is genetic drift.

Gene flow is the movement of alleles into or out of a population, generally due to patterns of migration.

Migration is the physical departure or arrival of organisms between different populations or geographical locations.

Natural selection is the increased prevalence of "favorable" traits and genes, and the decline in prevalence of "unfavorable" traits and genes.

Mutation is a genetic alteration that results in a new DNA sequence. Mutation is responsible for the creation of new alleles, traits, and phenotypes.

For Hardy-Weinberg equilibrium to be in effect, five conditions must be met:

1. Large Population

2. Isolated populations (no immigration or emigration)

3. No spontaneous mutations

4. Mating is random

5. No natural selection

Hardy-Weinberg equilibrium describes no change in genotypic frequencies over multiple generations. This is not likely to be seen in nature due to multiple factors, but it can be a useful theory for scientists. Hardy-Weinberg equilibrium requires no immigration or emigration, a large population, random mating, and no spontaneous mutations (all of which are virtually unavoidable in nature). Natural selection would violate these conditions.

Hardy-Weinberg equilibrium describes no change in the genotypic frequencies of a population. After one generation, assuming random mating, a closed system, a large population, and no random mutations, the genotypic frequencies of the population will not change.     

Since the population is in Hardy-Weinberg equilibrium, we can use the following equation to determine the genotypic frequencies for the allele in question:

In this equation,  represents the frequency of the dominant allele and  represents the frequency of the recessive allele. The  portion of the expression represents the frequency of heterozygotes in the population. Using the allelic frequencies given in the question, we can calculate the percentage of heterozygous individuals.

32% of the population is heterozygous for the trait.